Posted
by
Soulskillon Friday April 05, 2013 @01:01PM
from the or-we-could-keep-burning-dead-dinosaurs dept.

An anonymous reader writes "Researchers at Virginia Tech say they've had a genuine breakthrough in alternative energy production that could shake up the world's energy structure. Specifically, they've hit on a way to derive large amounts of hydrogen from any plant source. The method uses renewable natural resources, releases almost no greenhouse gasses, and needs no costly or heavy metals. The key is using xylose, the most abundant simple plant sugar, to produce a large quantity of hydrogen that previously was attainable only in theory."

You could take that H2 and combine it with some carbon and some oxygen. I believe these new fuels are called hydrocarbons. My understanding is that these revolutionary molecules have a high energy density and combusting them should be a reasonable way to use it to power vehicles.

1. Just how much energy would it take to recombine hydrogen with carbon and oxygen to make hydrocarbons?2. Hydrogen still delivers more bang per unit of measure than any hydrocarbon.3. Burning hydrocarbons creates greenhouse gases.

2. Hydrogen still delivers more bang per unit of measure than any hydrocarbon.

That depends entirely on your unit of measure. Units of volume are pretty important too, and you have to get compressed hydrogen up to around three thousand atmospheres before it has the same volumetric density as gasoline.

It's called a Sabatier reaction. It is the reaction of hydrogen and carbon dioxide, under pressure, at 300-400 C, in the presence of a nickel catalyst to produce methane and water. The methane can be transported in the existing natural gas pipeline system or used by a reforming fuel cell. The methane can also be used in one of the variations of the Fischer-Tropsch reactions to make liquid fuels.

The Honda fuel cell car can go 240 miles between fillups. That's nothing breakthrough, but it's far enough. You can also refill it in a few minutes at a hydrogen equipped gas station. I know the technology needs to get better, but the technology to use hydrogen is already here. The problem has always been how to get hydrogen efficiently. These seems to have solved that, hopefully.

Indeed, this is not a solution for the fuel-cell problem, but at this point personal transportation is not important. The immediate and most significant aspect of this technology is that it may be a viable replacement for fossil fuels in the not too distant future. If it works, the next problem will be supplying the enormous amounts of xylose needed to maintain the necessary levels of hydrogen production, and that may yet prove to be a challenge regardless of the efficiency of the process.

They got the storage down pretty well I think. There's hydrogen cars drive around all over my town. I also know some off-road guys that use it in competition because they get their trucks at crazy angles sometimes and liquid fuel becomes problematic when the trucks at a 90 degree angle.

Fuel cells give you a decent range and converting gas stations to also store hydrogen is probably going to be easier than revamping the entire electrical system to support any non trivial amount of charging at home.You could also use large home based fuel cells to generate electricity at source avoidiung transmission losses.

What happens when all the commuters get home and put their cars on charge between 5-7

There is battery life. But what we really need is recharge time. You can fill a hydrogen car in about as much time it takes to fill a gasoline car. If you can get 300 miles per charge, and fill it in under 5 minutes, and fuel costs is low enough, it would make it viable.

However if you travel and you go beyond the storage limit even, and it will take you 6 hours to recharge, you will probably not want that car, even though it is only a 5 times a year occurrence.

Today's lithium batteries can be charged to 80% in less than 20 minutes (a normal road trip pit stop)--no matter how big they are--and this will only improve. All we need is the network of DC Quick Charge stations. Building out quick-charge infrastructure is orders of magnitude cheaper than building a hydrogen distribution system. Tesla is already doing it (with their "Supercharger" network), and cost is such a non-issue that they provide it as a free perk for their drivers. With their included solar pa

Hydrogen has the opposite problem that if you don't drive, you lose power. It leaks. Through a half inch of solid steel.

According to Nasa [nasa.gov], hydrogen will leak through microscopic pores in welds. But that is not the same as leaking directly through cast steel, and storage tanks can be cast as a single piece, without welds. Or a welded tank could have an additional layer of another material, such as aluminum, on the interior surface.

Holy shit that's a lot of technical problems. If the tank isn't kept ultra-cold (i.e. it's hot outside) it explodes. As you burn hydrogen, pressure drops, the hydrogen in the tank cools the metal ridiculously. And what's with this mass/volume of storage? That's good if you need transport, but not necessarily efficient to produce--gasoline could be 20 times as efficient and it would be 100% useless in space versus 2% efficient hydrogen. How do they compare?

Storing and transporting hydrogen is just too friggin' complex for econoboxes.

Pressure relief valve [wikipedia.org]. It's mentioned in the link. The article is discussing liquid Hydrogen, which is not being discussed for use in cars.

As you burn hydrogen, pressure drops, the hydrogen in the tank cools the metal ridiculously.

1. How fast do you think the Hydrogen is being released? Under normal conditions, normal thermal transfer should keep the tank warm.2. If it's a problem, waste heat will be used to warm the tank.

And what's with this mass/volume of storage? That's good if you need transport, but not necessarily efficient to produce--gasoline could be 20 times as efficient and it would be 100% useless in space versus 2% efficient hydrogen. How do they compare?

Not sure what you mean by this- why would a fuel that was 20 times more efficient than Hydrogen be useless in space?

Hydrogen has the opposite problem that if you don't drive, you lose power. It leaks. Through a half inch of solid steel.

According to Nasa [nasa.gov], hydrogen will leak through microscopic pores in welds. But that is not the same as leaking directly through cast steel, and storage tanks can be cast as a single piece, without welds. Or a welded tank could have an additional layer of another material, such as aluminum, on the interior surface.

The container needs a hole in it to get the hydrogen in and out. It will leak through the connection to the plumbing.

That being said, casing the container as a single piece is a very very good idea.

Electric cars sound great as long as you do not live in a flat. How do you connect to the power grid if you have to park out on the street? Most people cannot even park outside their own house let alone connect a power lead. If you live on the fourth floor you are not going to hang a power lead out the window:-) I do think that it is great tech but it is very limited.

Moving energy around in trucks is wasteful and slow compared to moving it through the already established electrical grid.
The only reasons we stay with liquid fuels are that battery and charging technology doesn't yet supply the needed mileage range and quick recharge rate.
And to keep oil companies and gas stations in business.

2. Resistance is not the only issue with electricity transmission. As I stated, so is inductance and capacitance is present in AC systems and gets larger as the conductor get longer. induction leaches by causing voltages in nearby objects and capacitance stores energy and resists voltage change. This is the r

What you overlook is that this process uses biomass (ie, waste plant matter) to produce H2 in a process with 100% energy gain (the energy out is more than the energy in) not to mention that the energy put in could be waste heat, resulting in essentially free H2. H2 can be used in portable capacities, such as cars. Solar cannot fulfill these particular needs, although it could be used to create H2, at a much lower level of efficiency.

Boeing Co., the world’s largest aerospace company, plans to deliver its first commercial scale high-efficiency solar-power cells for Earth-based electricity production in January.

The concentrating photovoltaic cells, developed by Boeing’s Spectrolab unit for satellites and the International Space Station, can convert as much as 39.2 percent of sunlight into electricity, Chicago-based Boeing said today in a statement.

It is not efficient in terms of watts/m^2, but the more important metric is watts/$. A square meter PV panel costs hundreds of dollars. A square meter of corn, sugar cane, or switchgrass costs less than one dollar.

What you're forgetting is cost. Let me give you a car analogy. Let's say you have a choice between buying two identical cars. One gets 30 MPG and costs $30k, and the other gets 60 MPG but costs $60k. Let's assume that you drive 15,000 miles a year, and fuel will cost $4 a gallon. You would have to drive the car 450,000 miles before you would break even in costs. That's assuming that everything else is identical in the car.

So how does that relate to plants vs solar panels? How much does a solar pane

The counter is that traditional crystalline silicon panels are expensive to produce, and even cheaper (and less efficient) amorphous ones still require a significant energy input to manufacture. Light sensors and tracking motors need maintenance. The panels themselves can get damaged and need replacement. A simple, robust plant could be grown for comparatively low cost, and even though the percentage of conversion is much lower, requiring much larger swaths of land for energy generation, it could potenti

looking solely at the sunlight->electricity aspect, that's true, but in the plant process you also get CO2->O2 conversion, which solar cells don't do, and plants may require less energy input to cultivate and harvest (or at least less _new_ energy input, if we can use waste material from other plant-using processes like agriculture). After all, isn't one of the perennial gripes about solar panels the amount of energy and materials it takes to manufacture them?

converting plant matter into electricity or hydrogen wouldn't be efficient : photosynthesis converts 3-6% of solar energy and converting this chemical energy into hydrogen and theninto electricity won't improve on this; while a decent solar panel reaches at least 10% (more like 14-19%), into electricity.

How many solar sells make themselves from seeds? Or act as a battery while they collect the energy, and simply wait ready to be used? If you had 1/10th of a square mile with which to make the most energy possible, sure you would want solar cells. But if you had 100 square miles, photosynthesis would be far more economical.

Solar panels are improving, but you need to look at the total energy balance. Don't forget about the embedded energy used in making a solar panel, and that you can easily have 100-1000x the surface area growing vegetation than you would have covered by solar panels. They're complementary technologies, each with their own market. No one technology will replace fossil fuels, but this tech will give Hydrogen a bigger place in the energy market.

converting plant matter into electricity or hydrogen wouldn't be efficient : photosynthesis converts 3-6% of solar energy and converting this chemical energy into hydrogen and theninto electricity won't improve on this; while a decent solar panel reaches at least 10% (more like 14-19%), into electricity.

True in terms of conversion efficiency. But once you look at cost efficiency, the balance flips the other way. You can cover the entire planet in plants for less than the cost of a single solar panel, because plants grow and spread by themselves.

In fact there's millions of tons of plant matter we already gather (weeds and unused portions of food crops like corn stalks) which we currently burn or bury. All that could be converted into hydrogen essentially for free via a process like this. In that case the conversion efficiency becomes meaningless because the opportunity cost is negative: Right now it costs you to get rid of the waste plant matter. If you convert it into hydrogen instead, that means you get both the benefit of the hydrogen as a fuel and you don't have to pay to dispose of the plant matter.

This results in an energy efficiency of more than 100 percent — a net energy gain.

So I think it is all a load of bull shoveled by 'we want to make people feel good about owning cars' lobby. This is true for most of the hydrogen as 'alternative energy' articles that show up here every other week. Hydrogen is an energy storage medium not an energy source.

I find it very hard to believe that they are somehow going to get more energy out of plant matter than biodiesel or simply burning it. Hydrogen may be clean, but it's certainly not convenient. I my area, they can run cars on trash. Trash is burned in a Waste-to-Energy facility, and cars are recharged from the electricty.

Even more unbelievable (at least for a "layman" like me) is this claim:

"Even more appealing, this reaction occurs at low temperatures, generating hydrogen energy that is greater than the chemical energy stored in xylose and the polyphosphate. This results in an energy efficiency of more than 100 percent — a net energy gain."

The "more than 100 percent" claim is a bit strange, but might just be poor syntax. Perhaps they meant a more than 100% gain vs simply burning, or just classify biodesel as the 100% starting point, so a 10% increase means we are actually giving 110%

As for the low temperature bit, isn't that exactly what the first law of thermodynamics dictates? Energy can't simply be created, so the total amount of energy produced will always be constant. If we lost less energy to heat, more energy would be converted to f

You are being a little bit pedantic. They are referring to usable energy inputs / usable energy outputs.

As a counter example, look at ethanol. It requires a lot of cooking with natural gas to convert corn into a usable fuel. I have heard arguments that it would be more efficient to run cars on natural gas. (I don’t think that is true anymore – ethanol production can become a lot more efficient.)

The point is, biodiesel burns dirty and is inefficient. We can burn hydrogen at almost 100% efficiency. The reaction in which they turn the plant material into hydrogen likely happens in a closed cycle. The entire reaction is contained. So they could cycle through the same material several times to get the most out of it. Where-as, with diesel, you combine it with ambient air that's and an unknown temperature, moisture and oxygen content, light it and hope for the best.

TFA says "Even more appealing, this reaction occurs at low temperatures, generating hydrogen energy that is greater than the chemical energy stored in xylose and the polyphosphate. This results in an energy efficiency of more than 100 percent â" a net energy gain." Truly we will have to reexamine the laws of thermodynamics in light of this discovery!

I don't think they're claiming to violate the laws of thermodynamics; it appears they're just using an inappropriate reference value. Based on the rest of the quote, it looks like they are using the 100% efficiency energy output from burning the biomass as the reference and comparing it to the net energy output using this method. I base that on the context from the rest of the quote:

...Even more appealing, this reaction occurs at low temperatures, generating hydrogen energy that is greater than the chemical energy stored in xylose and the polyphosphate. This results in an energy efficiency of more than 100 percent — a net energy gain. That means that low-temperature waste heat can be used to produce high-quality chemical energy hydrogen for the first time. Other processes that convert sugar into biofuels such as ethanol and butanol always have energy efficiencies of less than 100 percent, resulting in an energy penalty.

The energy stored in xylose splits water molecules, yielding high-purity hydrogen that can be directly utilized by proton-exchange membrane fuel cells. Even more appealing, this reaction occurs at low temperatures, generating hydrogen energy that is greater than the chemical energy stored in xylose and the polyphosphate. This results in an energy efficiency of more than 100 percent â" a net energy gain. That means that low-temperature waste

Electric cars are a given; they simply have way to many enticing benefits (tremendous power, simplicity).

No matter how much batteries improve, we'll simply not be able to fill them as conveniently we do normal vehicles. Putting plugs everywhere is totally impractical.

Hydrogen solves all of the issues with batteries while still giving us electric cars. Sure there are some issues now but as articles like this show, over time there will be advances in both generating and storing hydrogen. It's only a matter of time before hydrogen cars totally replace electric cars because of simple utility, and (sadly) the ability to have a more normal taxing structure applied to fuel.

Actually we could give them transponders and put electrical infrastructure in the roads for inductive chargers, whereby your car could report your account to the utility company and the utility could charge for your power usage.

Alternately, we could just let the Government do it, but when you renew your registration you have to turn in your mileage, and they forward that to your utility, and bill you.

While hydrogen can be used as a fuel, it makes more sense for it to be used in ammonia production. The #2 most-produced chemical is ammonia and it is most commonly produced using natural gas which produces CO2 as a by-product.

Ultimately, the true test of this new process is how do the costs compare to steam-reforming of natural gas into hyrdogen?

The team liberates the high-purity hydrogen under mild reaction conditions at 122 degree Fahrenheit and normal atmospheric pressure. The biocatalysts used to release the hydrogen are a group of enzymes artificially isolated from different microorganisms that thrive at extreme temperatures, some of which could grow at around the boiling point of water.

How much energy will it take to produce the biocatalysts and will that reduce the EROEI [wikipedia.org] to less than 1?

I thought this stuff should be left up the scientists at big oil to pioneer this research? We don't need no more gubmint funded research at educational institutions. too much big goverment is bad. Bad I say.

But if they think it's a "game changer," I suggest that the researchers quickly engage in a remedial math course. Plants are very inefficient solar collectors, land area is limited, using "natural" sources will quickly lead to the destruction of every natural environment if we were so silly as to try and replace the 160 exajoules per year provided by petroleum.

So, useful for small things. Maybe, one day, if the process is cheap enough and energy positive. Third world countries may benefit. Industrial scale

The majority of input energy would be solar, growing the plants. the machinery used to harvest and transport it wouild run on electriciy and fuel cells just like everything else. It is just a matter of A) generating enough plant matter, and B) getting the infrastructure to critical mass to become sel sustaining.

Sure, it sounds far fetched. But hey, you have to start some where some time. Right?

I am sure big oil would gladly shift to a new technology.Here is the problem...Gasoline offers the following advantages. High Energy Density. Can be stored and shipped easily, relativity safe (compared to other that would kill you at the first smell or explode more violently) Doesn't require a high infrastructure to deal with.

Now if we can get Hydrogen cheap and fuel cells cheap enough to make affordable cars that people will buy. I can see the big oil companies starting to shift to the hydrogen market. They already have ways of shipping, and retailers for their product. They will just switch products.

Big oil already [aol.com] owns many of the worlds top green energy companies. For example BP has been one of the top producers of solar cells for many years. Your ire would be better directed at those actually putting up road blocks to green energy.

Energy companies are in the business of selling energy, and frankly they typically don't care what that source of energy is. Most companies sell gas, propane, diesel, and natural gas at a minimum and many have business relationships that go far beyond that.